Effect of hydrogen peroxide-based bleaching agents on the color dimensions and surface roughness of different milled restorative dental materials.

PURPOSE: To compare the color dimensions, color discrepancies (ΔE00), and surface roughness of milled materials before and after the application of a bleaching agent. MATERIAL AND METHODS: A total of 10 extracted molars were obtained. Each tooth was cut in transversal sections, to create discs (3 mm thick, 10 mm diameter) (control group). Disk specimens of 8 materials were fabricated: polymethyl methacrylate (PMMA) interim material (PMMA-Telio group), 2 resin nanoceramics: (RNC-Ultimate group) and (RNC-Cerasmart group), 2 hybrid ceramics: (HC-Shofu group) and (HC-Enamic group), lithium disilicate (LD-Emax group), zirconia reinforced glass ceramic (ZGC-Suprinity group), and zirconia (Zr group) (n=10). Color measurements were obtained using a spectrophotometer before and after applying 35% hydrogen peroxide-based bleaching agent. Pre- and post-bleaching surface roughness analysis were completed using a profilometer. RESULTS: Significant L*, a*, b*, and ΔE00 values differences were found (P < .05). Color discrepancies (ΔE00) ranged from 0.30 ± 0.14 to 4.82 ± 0.10. The highest color discrepancies were measured on the PMMA-Telio group, while the lowest color discrepancies were computed on the ZGC-Suprinity, RNC-Ultimate, and RNC-Cerasmart. Significant surface roughness differences were found (P <.05). The largest increase of surface roughness values between the pre- and post-bleaching measurements was obtained in the PMMA-Telio group with a mean ΔSa value of 4.73 ± 3.02, while the largest decrease of surface roughness values between the pre- and post-bleaching measurements was obtained in the Zr-InCeram group with a mean ΔSa value of -1.58 ± 0.10. CONCLUSIONS: The milled materials tested showed significant pre- and post-bleaching color and surface roughness discrepancies. Int J Prosthodont. doi: 10.11607/ijp.8359.

Adsorption Removal of Mo(VI) from an Aqueous Solution by Alumina with the Subsequent Regeneration of the Adsorbent.

Industrial wastewater is the main source of an excessive amount of molybdenum (Mo) in natural ecosystems. It is necessary to remove Mo from wastewater before it is discharged into the environment. Molybdate ion(VI) is the most common form of Mo in natural reservoirs and industrial wastewater. In this work, the sorption removal of Mo(VI) from an aqueous medium was evaluated using aluminum oxide. The influence of such factors as the pH of the solution and the temperature was evaluated. Three adsorption isotherms, namely, Langmuir, Freundlich and Temkin, were used to describe the experimental results. It was found that the pseudo-first order kinetic model better fits the kinetic data of the adsorption process, and the maximum Mo(VI) adsorption capacity was 31 mg/g at 25 °C and pH 4. The thermodynamic parameters indicated that the process of Mo(VI) adsorption on Al2O3 was exothermic and spontaneous. It was shown that the adsorption of Mo strongly depends on pH. The most effective adsorption was observed at pH values below 7. Experiments on adsorbent regeneration showed that Mo(VI) can be effectively desorbed from the aluminum oxide surface into a phosphate solution in a wide range of pH values. After the desorption of Mo(VI) in a phosphate solution, alumina was found to be suitable for repeating the procedure at least five times.

Solid State Processing of BCZT Piezoceramics Using Ultra Low Synthesis and Sintering Temperatures.

Lead-free (Ba0.92Ca0.08) (Ti0.95 Zr0.05) O3 (BCZT) ceramics were prepared by a solid-state route (SSR) using ultra-low synthesis (700 °C/30 min and 700 °C/2 h) and sintering temperatures (from 1150 °C to 1280 °C), due to prior activation and homogenization by attrition milling of the starting high purity raw materials for 6 h before the synthesis and of the calcined powders for 3 h before the sintering. The comparison of the thermal analysis of the mixture of the starting raw materials and the same mixture after 6 h attrition milling allowed to evidence the mechanisms of activation, resulting in a significant decrease of the perovskite formation temperature (from 854 °C down to 582 °C). The secondary phases that limit the functional properties of the ceramic and their evolution with the sintering conditions were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM), which allowed the design of a two-step sintering method to eliminate them. A pure tetragonal BCZT perovskite phase (P4mm, c/a = 1.004) and homogeneous ceramic microstructure was obtained for synthesis at 700 °C for 2 h and sintering with the use of a two-step sintering treatment (900 °C for 3 h and 1280 °C for 6 h). The best electromechanical properties achieved were d33 = 455 pC/N, kp = 35%, Qm = 155.

New Ceramic Multi-Unit Dental Abutments with an Antimicrobial Glassy Coating.

The choice of suitable materials and new designs in oral implantology and the subsequent enhancement of the characteristics of the dental implant developed is an important research topic with wide scope. The present work aims to develop a new multifunctional zirconia-ceria/alumina (Ce-TZP/Al2O3) composite with an antimicrobial glass-based coating to be used in multi-unit abutments compatible with commercially available Ti implants for peri-implantitis prevention. An airbrush spraying technique was effectively applied to coat the sintered ceramic composite starting from a glass powder suspension. This deposition technique was appropriate for obtaining continuous antimicrobial glass-based coatings with homogenous thickness (~35 µm) on ceramic dental implant components. The dental implant systems with the antimicrobial glassy coating were subjected to a mechanical integrity test following ISO 14801 to determine their long-term stability. The tested implant-coating structure seems to be stable under in vitro conditions with ultimate applied forces exceeding the maximum physiological occlusal loading force. This paper also presents a pilot clinical case report that shows peri-implant tissue around the mechanically stable glass coating with no signs of inflammation 1 year after implant insertion. This result is a preliminary probe of the durability and biological tolerance of the glassy material by the gingiva, as well as the antimicrobial effect on the peri-implant microbiota displayed by the coating.

Original vs compatible stock abutment- implant connection: An in vitro analysis of the internal accuracy and mechanical fatigue behaviour.

PURPOSE: To assess the internal accuracy and mechanical behaviour under cyclic loading after artificial aging of implant-supported crowns restored with original stock abutments and two compatible non-original stock abutments. METHODS: Forty-eight original internal hexagon connection implants were connected to different stock abutments. The samples were divided into three groups depending on the manufacturer of the abutment components (one original, two non-originals).Firstly, samples were cross-sectioned and observed by using Scanning Electron Microscope (SEM) to evaluate the internal accuracy in three different implant-abutment interface locations (platform, internal and screw).Further, cyclic fatigue loading was carried out according to the ISO Norm 14801 using dynamic testing machine under sinusoidal loads for 2,000,000 cycles at test frequencies of 2 Hz in air after thermocycling with 10,000 cycles at 5 °C and 55 °C in artificial saliva for aging simulation. RESULTS: Original abutment components presented the highest percentage of surface with tight contact with the implant in the three implant-abutment interfaces studied. Additionally, original configuration showed highest fatigue limit value and fatigue strength exponent (280 N and -0.054) than non-original 1 (225 N and -0.109) and non-original 2 (200 N and -0.101). CONCLUSION: Original abutment components provide better fit and mechanical results under cyclic loading than non-original configurations. The results obtained in this study seem to suggest that the use of the original stock abutments to implants leads to a more homogeneous load distribution between the components that can influence the long-term success of the restorations.

Mechanical Performance of Chairside Ceramic CAD/CAM Restorations and Zirconia Abutments with Different Internal Implant Connections: In Vitro Study and Finite Element Analysis.

(computer-aided design-computer-aided manufacturing) CAD/CAM monolithic restorations connected to zirconia abutments manufactured with a chairside workflow are becoming a more common restorative option. However, their mechanical performance is still uncertain. The aim of this study was to evaluate the mechanical behavior of a combination of a zirconia abutment and monolithic all-ceramic zirconia and lithium disilicate crown manufactured with a chairside workflow, connected to titanium implants with two types of internal connection-tube in tube connection and conical connection with platform switching. They were thermally cycled from 5 °C to 55 °C and were subjected to a static and fatigue test following ISO 14801. The fractured specimens from the fatigue test were examined by SEM (scanning electron microscopy). Simulations of the stress distribution over the different parts of the restorative complex during the mechanical tests were evaluated by means of (finite element analysis) FEA. The mechanical performance of the zirconia abutment with an internal conical connection was higher than that of the tube in tube connection. Additionally, the use of disilicate or zirconia all-ceramic chairside CAD/CAM monolithic restorations has similar results in terms of mechanical fracture and fatigue resistance. Stress distribution affects the implant/restoration complex depending on the connection design. Zirconia abutments and monolithic restorations seem to be highly reliable in terms of mechanical resistance.

Determination of the PIC700 Ceramic's Complex Piezo-Dielectric and Elastic Matrices from Manageable Aspect Ratio Resonators.

Achieving good piezoelectric properties, such as the widely reported d33 charge coefficient, is a good starting point in establishing the potential applicability of piezoceramics. However, piezoceramics are only completely characterized by consistent piezoelectric-elastic-dielectric material coefficient matrices in complex form, i.e., including all losses. These matrices, which define the various alternative forms of the constitutive equations of piezoelectricity, are required for reliable virtual prototyping in the design of new devices. To meet this need, ten precise and accurate piezoelectric dielectric and elastic coefficients of the material, including all losses, must be determined for each alternative. Due to the difficulties arising from the coupling of modes when using the resonance method, this complete set of parameters is scarcely reported. Bi0.5Na0.5TiO3-based solid solutions are already commercially available in Europe and Japan. Here, we report a case study of the determination of these sets of material coefficients (diα, giα, eiα and hiα; sE,Dαß and cE,Dαß; εTik and εSik; and ßTik and ßSik), including all losses, of the commercial PIC700 eco-piezoceramic. Plate, disk, and cylinder ceramic resonators of a manageable aspect ratio were used to obtain all the material coefficients. The validation procedure of the matrices is also given by FEA modeling of the considered resonators.

Cyclic Mechanical Fatigue Lifetime of Bi0.5Na0.5TiO3-Based Eco-Piezoceramics.

The mechanical strength and cyclic fatigue behavior of PIC700 commercial eco-piezoceramic disks are investigated under biaxial loading on unpoled and poled samples. The bending strength of unpoled samples was higher than those of poled ones. Fatigue tests were conducted under a load ratio of 10 at a frequency of 20 Hz with a sinusoidal waveform. The curve fitting for the S-N fatigue diagram is used to predict the lifetime of these eco-piezoceramics and describe their fatigue behavior. It was also found that the unpoled samples exhibited higher fatigue resistance than the poled ones. The fatigue limit of maximum load for ten million cycles of unpoled and poled samples was estimated to be 160 and 135 MPa, respectively. The detailed observations of the fatigue fracture surfaces by scanning electron microscopy (SEM) indicated that a wavy surface with a mixture of transgranular and intergranular fractures occurred preferentially in the case of the poled material. On the other hand, transgranular fractures seem to be predominant in the unpoled samples. It appears that the poling process causes the change in failure characteristics due to domain orientation that leaves an anisotropic stress field in the material. The poled ceramics possess a local stress concentration created by the orientation under the electric poling field of the 90° ferroelectric-ferroelastic domains. Under this local stress concentration, a microstructural degeneration is induced by domain switching under the cyclic load that accelerates crack growth, thereby reducing fatigue lifetime.

MgNb2 O6 Modified K0.5 Na0.5 NbO3 Eco-Piezoceramics: Scalable Processing, Structural Distortion and Complex Impedance at Resonance.

In this work, piezoceramics of the lead-free composition K0.5 Na0.5 NbO3 with an increasing amount of MgNb2 O6 (0, 0.5, 1, 2 wt.%) were prepared through conventional solid-state synthesis and sintered in air atmosphere at 1100 °C. The effect of magnesium niobate addition on structure, microstructure and piezoelectric properties was evaluated. The ceramics maintain the orthorhombic Amm2 phase for all compositions, while an orthorhombic Pbcm secondary phase was found for increasing the concentration of MgNb2 O6 . Our results show that densification of these ceramics can be significantly improved up to 94.9 % of theoretical density by adding a small amount of magnesium-based oxide (1 wt.%). Scanning electron microscopy morphology of the 1 wt.% system reveals a well-packed structure with homogeneous grain size of ∼2.72 µm. Dielectric and piezoelectric properties become optimal for 0.5-1.0 wt.% of MgNb2 O6 that shows, with respect to the unmodified composition, either higher piezoelectric coefficients, lower anisotropy and relatively low piezoelectric losses (d33 =97 pC N-1 ; d31 =-36.99 pC N-1 and g31 =-14.04×10-3  mV N-1 ; Qp (d31 )=76 and Qp (g31 )=69) or enhanced electromechanical coupling factors (kp =29.06 % and k31 =17.25 %).

Original versus nonoriginal cast-to-gold abutment-implant connection: Analysis of the internal fit and long-term fatigue performance.

STATEMENT OF PROBLEM: Restoring implants with nonoriginal abutments is common. However, studies that evaluated compatible abutments with long-term fatigue performance are lacking. PURPOSE: The purpose of this in vitro study was to assess the internal fit and the cyclic fatigue life after artificial aging of 3 implant-abutment configurations restored with 1 original and 2 compatible nonoriginal cast-to-gold abutments. MATERIAL AND METHODS: Forty-eight original internal hexagon connection implants were connected to 3 different brands of abutments (n=16): 1 original to the implant system and the other 2 with nonoriginal abutments. Internal fit and the percentage of surface with tight contact were assessed by scanning electron microscopy in 12 cross-sectioned specimens (n=4) at 3 different areas (platform, internal, and screw). Thirty-six implant-abutment-crown specimens (n=12) were immersed in artificial saliva and thermocycled for 10 000 cycles between 5 °C and 55 °C. Subsequently, a cyclic load test, as per International Organization for Standardization (ISO) Standard 14 801, was completed in a universal testing machine at 2 Hz in air. RESULTS: The original abutments presented the best fit and highest percentage of tight contact in the internal areas. In addition, the original abutments showed the lower cyclic fatigue strength degradation and the highest long-term success. CONCLUSIONS: Occlusal loads are transferred more homogenously through the system when original abutments are used because of the better fit between the internal components, leading to increased fatigue resistance.

Fatigue fracture resistance of titanium and chairside CAD-CAM zirconia implant abutments supporting zirconia crowns: An in vitro comparative and finite element analysis study.

STATEMENT OF PROBLEM: Zirconia abutments with a titanium base are promising candidates to substitute for titanium abutments based on clinical studies reporting good short-term survival rates. However, information on the long-term performance of zirconia abutments supporting ceramic crowns is scarce. PURPOSE: This in vitro comparative and finite element analysis study compared the fatigue life performance of ceramic computer-aided design and computer-aided manufacturing (CAD-CAM) monolithic restorations and zirconia abutments fabricated with a chairside workflow connected to a titanium interface versus titanium abutments. MATERIAL AND METHODS: Twenty-two internal connection implants were divided into 2 groups, one with a zirconia abutment and monolithic ceramic zirconia crown (ZZ) and the other with a titanium abutment and zirconia crown (TiZ). They were subjected to a fatigue test to determine the fatigue limit and fatigue performance of each group as per International Organization for Standardization (ISO) 14801. Microstructural analysis of the fracture surfaces was conducted by using a scanning electron microscope (SEM). Simulations of the in vitro study were also conducted by means of finite element analysis (FEA) to assess the stress distribution over the different parts of the restoration. RESULTS: The fatigue limit was 250 N for the TiZ group and 325 N for the ZZ group. In both groups, the screw was the part most susceptible to fatigue and was where the failure initiated. In the zirconia abutment models, the stress on the screw was reduced. CONCLUSIONS: Chairside CAD-CAM zirconia abutments with a titanium base supporting zirconia crowns had higher fatigue fracture resistance compared with that of titanium abutments.

Effect of cementation and aging on the marginal fit of veneered and monolithic zirconia and metal-ceramic CAD-CAM crowns.

STATEMENT OF PROBLEM: Marginal fit of zirconia restorations is an important criterion for their long-term success. However, in spite of the wide use of zirconia in dentistry, the relationship between marginal fit and low-temperature degradation from aging is unclear. PURPOSE: The purpose of this in vitro study was to compare the marginal adaptation of veneered and monolithic zirconia and metal-ceramic computer-aided design and computer-aided manufacturing (CAD-CAM) crowns before and after cementation and to evaluate the influence of artificial aging on the adaptation of zirconia crowns. MATERIAL AND METHODS: Seventy-two standardized dies were prepared to receive a posterior crown and randomly divided into 6 groups (n=12) as per the material and the presence or not of cement: metal-ceramic, veneered zirconia, and monolithic zirconia. The zirconia groups were subjected to accelerated low-temperature degradation through hydrothermal aging in an autoclave at 131 °C and 0.17 MPa for 5 and 20 hours. A scanning electron microscope with a magnification of ×1000 was used for marginal adaptation measurements, and X-ray diffraction (XRD) was used to characterize phase transformation degradation. The data were statistically analyzed using 2-way ANOVA, repeated measures ANOVA with Greenhouse-Geisser correction, and the t test (α=.05). RESULTS: No significant differences in the marginal discrepancy were recorded among the analyzed groups. The presence of cement did not influence marginal fit in any treatment group. No significant differences were observed in the marginal adaptation values before and after aging (P>.05). After 20 hours of aging, the monoclinic phase increase to 8.3% on veneered zirconia and to 3.1% on monolithic crowns. CONCLUSIONS: Monolithic and bilayer CAD-CAM zirconia crowns showed marginal gaps that were within an acceptable range of clinical discrepancy, regardless of cementation. Marginal adaptation was not influenced by aging. Low-temperature degradation did not lead to a significant transformation from the tetragonal to monoclinic phase.

Zirconia Reduced Graphene Oxide Nano-Hybrid Structure Fabricated by the Hydrothermal Reaction Method.

In this work, we report an available technique for the effective reduction of graphene oxide (GO) and the fabrication of nanostructured zirconia reduced graphene oxide powder via a hydrothermal method. Characterization of the obtained nano-hybrid structure materials was carried out using a scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR). The confirmation that GO was reduced and the uniform distribution of zirconia nanoparticles on graphene oxide sheets during synthesis was obtained due to these techniques. This has presented new opportunities and prospects to use this uncomplicated and inexpensive technique for the development of zirconia/graphene nanocomposite powders.

The Influence of Wire Electrical Discharge Machining Cutting Parameters on the Surface Roughness and Flexural Strength of ZrO2/TiN Ceramic Nanocomposites Obtained by Spark Plasma Sintering.

In this work, we characterized the mechanical and electrical properties of zirconia-based ceramic nanocomposites reinforced with 30 and 40 vol. % TiN and fabricated by spark plasma sintering. In addition to their improved mechanical performance, these compositions have sufficient electrical conductivity to allow wire electrical discharge machining (WEDM). The influence of WEDM variables on the roughness and the mechanical strength of samples was analyzed after each cut. The experimental results showed that the roughness of machined surfaces can be reduced by variations in WEDM manufacturing regimes, and, consequently, a drastic drop in flexural strength of workpieces can be avoided. Furthermore, the composites with higher content and homogeneous distribution of the conductive phase exhibited better surface quality as well.

Mechanical fatigue behaviour of different lengths screw-retained restorations connected to two designs prosthetic connection level.

The aim of this work is to compare the mechanical fatigue behaviour of different crown heights of single crown implant restorations made over two different internal hexagonal titanium dental implant connection levels. Two different groups of internal hexagonal connection were studied: (a) TL group (N = 26) included implants with a transmucosal connection (12.2 mm height and 4.8 mm width) and (b) BL group (N = 26) composed by implants at a bone level connection (10 mm height and 3.8 mm width). Two subgroups (N = 13) were established for each connection level according to crown heights (TL10 = 10 mm, TL15 = 15 mm, BL12 = 12 mm, BL17 = 17 mm). Dynamic load tests were carried out according to ISO Norm 14801. Failed samples and fracture surfaces were analysed with an optical and scanning electron microscope (SEM). The fatigue limit and the fatigue strength degradation (fatigue strength exponent) decreases with increasing crown height (5 mm) in both groups of internal hexagonal titanium dental implant connection levels. Consequently, the mechanical integrity of internal hexagonal dental implants varies with the height of the crown. An increase of 5 millimetres in the crown height appears to significantly decrease the fatigue life of both types of dental implants.

Current state-of-the-art and future perspectives of the three main modern implant-dentistry concerns: Aesthetic requirements, mechanical properties, and peri-implantitis prevention.

The idea of permanent tooth replacement goes back to the year 2000 BC at least, when carved bamboo pegs were used to replace missing teeth in ancient China. The phenomenon of osseointegration, however, was not verified until the mid-1960s, when Branemark discovered that titanium could integrate to bone. Since then, the osseointegration capacity of implants has been profoundly investigated and implants as such have evolved enormously in all possible aspects, from material selection and processing to specific surface engineering, among many others. This review article, in particular, focuses on dental implants and aims to introduce the main concerns involved in modern dentistry, concentrating especially on the importance of finding an effective way to prevent peri-implantitis. In this sense, strategies such as shifting from metal to ceramic implant components and applying novel antimicrobial antibiotic-free coatings seem to be taking the lead. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2019.

Wear Behavior of Graphene-Reinforced Alumina⁻Silicon Carbide Whisker Nanocomposite.

In the present work, the tribological properties of graphene-reinforced Al2O3-SiCw ceramic nanocomposites fabricated by spark plasma sintering were studied against alumina ball. Compared with pure ceramic, the wear resistance of these nanocomposites was approximately two times higher regardless of the applied load. It was confirmed by Raman spectroscopy that the main factor for the improvement of the wear resistance of the Al2O3-SiCw/Graphene materials was related to the formation of protecting tribolayer on worn surfaces, which leads to enough lubrication to reduce both the friction coefficient, and wear rate.

Original vs. non-original abutments for screw-retained single implant crowns: An in vitro evaluation of internal fit, mechanical behaviour and screw loosening.

OBJECTIVES: To assess the internal accuracy, mechanical behaviour under static load and screw loosening before and after cyclic loading of implant-supported crowns restored with original components or with two compatible non-original brands. MATERIALS AND METHODS: Sixty-three dental implants were divided into three groups (n = 21 each): Group 1 used original components, and groups 2 and 3 used non-original components. Internal accuracy was measured throughout a cross section of the sample groups (n = 8) using scanning electron microscopy (SEM) to evaluate the fit for implant-abutments, implant-crowns and crown-abutments. To evaluate load-bearing capacity, eight samples from each group were loaded until fracture according to ISO Norm 14801. The removal torque value (RTV) was evaluated in the screws connecting the crown with the abutment and the abutment with the implant before and after cyclic loading (2 x 106 cycles) in five samples from each group. The data were analysed using the Kruskal-Wallis test (p < 0.05). RESULTS: Statistically significant differences were found among the mean crown-abutment gaps measured in Group 1 (9.3 µm), Group 2 (45.4 µm) and Group 3 (44.9 µm). Higher values for mean load-bearing capacity were found in Group 1 (1,098 N) than in groups 2 and 3 (1,057 and 973 N, respectively); however, these differences were not statistically significant. Original abutment-implant screws exhibited lower percentages of torque reduction than the non-originals. CONCLUSIONS: Enhanced fit is expected when original components are used. The original abutments exhibited lower percentages of torque reduction after cyclic loading than non-originals.

Evaluation of the Mechanical Behavior and Marginal Accuracy of Stock and Laser-Sintered Implant Abutments.

PURPOSE: The aim of this study was to evaluate the marginal accuracy and mechanical behavior of implant-supported crowns restored with original stock abutments and nonoriginal computer-aided design/computer-assisted manufacture laser-sintered abutments. MATERIALS AND METHODS: A total of 26 implants were divided in two groups (n = 13 each) as follows: implants connected to original stock abutments (OS) and implants connected to nonoriginal laser-sintered abutments (LS). Of these, 10 samples were cross-sectioned to measure the marginal accuracy under a scanning electron microscope. In addition, 16 samples were used to study the mechanical behavior. Two tests were performed: (1) static load and (2) dynamic load after thermocycling with artificial saliva. RESULTS: OS exhibited the best marginal accuracy; however, the LS gap was within the clinically acceptable range of marginal discrepancy. No significant differences were found in the mechanical tests. CONCLUSIONS: Both abutments are acceptable alternatives to restore implants, although the original abutments showed better fit than nonoriginals.

New ZrO2/Al2O3 Nanocomposite Fabricated from Hybrid Nanoparticles Prepared by CO2 Laser Co-Vaporization.

Alumina toughened zirconia (ATZ) and zirconia toughened alumina (ZTA) are currently the materials of choice to meet the need for tough, strong, and bioinert ceramics for medical devices. However, the mechanical properties of ZrO2/Al2O3 dispersion ceramics could be considerably increased by reducing the corresponding grain sizes and by improving the homogeneity of the phase dispersion. Here, we prepare nanoparticles with an intraparticular phase distribution of Zr(1-x)Al(x)O(2-x/2) and (γ-, δ-)Al2O3 by the simultaneous gas phase condensation of laser co-vaporized zirconia and alumina raw powders. During subsequent spark plasma sintering the zirconia defect structures and transition alumina phases transform to a homogeneously distributed dispersion of tetragonal ZrO2 (52.4 vol%) and α-Al2O3 (47.6 vol%). Ceramics sintered by spark plasma sintering are completely dense with average grain sizes in the range around 250 nm. Outstanding mechanical properties (flexural strength σf = 1500 MPa, fracture toughness KIc = 6.8 MPa m(1/2)) together with a high resistance against low temperature degradation make these materials promising candidates for next generation bioceramics in total hip replacements and for dental implants.